Dental chair.



PATENTED SEPT. 19, 1905.

PLE. CASE. DENTAL CHAIR.

APPLICATION FILED AUG. 7. 1903.

3 SHEETS-SHEET 1.

INVENTOR F/mizk t. Caae WITNESSES:

W ATTORNEY PATENTED SEPT. 19, 1905.

P. E. CASE. DENTAL CHAIR.

APPLICATION FILED AUG. 7. 1903.

3 SHEETSSHEET 2.

I I I ll 1 M| |HHn I I I H I MH IHMHH I I I IH W No. 799,972. PATENTEDSEPT. 19 1905.

' P. B. CASE.

DENTAL CHAIR.

APPLICATION FILED AUG. 7, 1903.

3 SH BBTS-SHEET 3.

WITNESSES INVENTOR l FrmtECase v 7 I BY W TTORNEY U ITED sT Tns PATENTOFFICE.

FRANK E. cAsE, or CANTON, OHIO.

DENTAL CHAIR.

Specification of Letters Patent.

Patented Sept. 19, 1905.

Application filed August '7, 1903. $erial No. 168,555.

following is a specification.

The invention relates to a pump for elevating and lowering theverticallyextensible parts of a chair-base; and the objects of theimprovements are to provide a release-valve in the pump by which therate of descent can be regulated and controlled, together withreadily-detachable means for operating the pump-plunger and therelease-valve. These objects are attained by the arrangement,construction, and mechanism illustrated in the accompanying drawings, inwhich Figure 1 is a perspective vertical section of the chair-base,showing the pump in place; Fig. 2, a vertical section of the pump in thelongitudinal middle line, showing the outline of the base in brokenlines; Fig. 3, a perspcctive view of the pump, showing some of its partsdetached and opposite their proper places.

Similar numerals refer to similar parts throughout the drawings.

The floor-plate 1 is preferably circular in form, and on its upper sideis provided the annular flange 2. The base 5 is preferably formed as acylinder, with its sides somewhat flattened, and is open above, below,and in front. The base terminates below in the external angular flange6, which is continued across the opening in front to complete thecircle, and this flange rests and rotates on the floor-plate flange. Thebox-standard 9 is formed similar in section to the base and telescopestherein, being provided with the usual vertical grooves forthecorresponding tongues formed in the base, and the body-standard 12 islikewise formed and telescopes in the boxstandard, being provided withthe similar grooves for the corresponding tongues in the box-standard.The body of the chair (not shown) is mounted on the body-standard and israised and lowered by the'elevation and depression of the respectivestandards.

The pump-block 15 is supported in the base by the lugs 16, formed. nearthe forward edges on its sides and near the top, the inclined loweredges 17 of which lugs hooking over the bosses which are formed near thetop on the forward edges of the base, and it isheld in position on thesesupports by the stay-pin located on the forward part of the base-flange,which pin enters the corresponding recesses 20 in the under side of thebottom. The oil-reservoir 32 is formed in the upper part of thepump-block, and the plunger-cylinder 33 is preferably located in theforward part of the reservoir and is screwed into the'socket 34, whichis provided for it in the thick bottom 35 of the pump, the

washer 36 being provided on the lower end of the cylinder to packagainst the bottom of the socket and make a tight joint.

The release-tube 37 is preferably located in the rear part of thereservoir and is screwed into the socket 38, which is provided for it inthe bottom of the block, the shoulders 37 being preferably provided onthe tube to make 'a tight fit against the bottom of the reservoir, andthe piston-cylinder 39 is preferably located on the rear side of theblock and is screwed into the socket 40, which is provided for it in therear extension 41 of the bottom of the block, and the upper end of thecylinder is held in the collar 42, which is formed on the upper rearside of the block. The main port 43 is located in the bottom of theblock and extends from the piston-cylinder socket directly forward to apoint under the plunger-cylinder socket, with which it communicatesthrough the aperture 44 in the bottom of this socket, and therelease-port 45 communicates from the main port to the bottom of therelease-tube socket.

The check-valve 46 is formed in the lower end of the plunger-cylinderand preferably comprises a ball-valve resting in a cup and normally heldup against its seat by a coilspring, which spring is sustained by theinner rim of the packing-washer 36. The main valve 47 is formed in thelower end of the plunger 48 and preferably comprises a ball-valveresting in a cup and normally held up against its seat by a coilspring,which spring is sustained by the bushing 48", which is screwed into thelower end of the plunger. The plunger is reduced in diameter above themain valve, thereby forming the annular port 49, into which port the oilenters from the reservoir through the apertures 50 in theplunger-cylinder located near the bottom of the reservoir. Thescreen-box 51 is preferably provided around these apertures to keep outdirt or grit. The

valve-ports 52 communicate between the annular port and the main valve.The bell-flange 53 is formed on the upper end of the plunger andoperates in and neatly fills the aperture 54:.

which is provided for it in the top of the The rim of the bell-flangeisadapted pump. to telescope outside of the plunger-cylinder,

and the plunger is normally held up bythecoil-spring 55, which islocated around the cylinder between the screen-box andthe bellflange.

The plunger is the right side of the chair to the reanfrom the end ofthe pump-shaft 57, which shaft is transversely journaled in.the forwardside of the block. The arms 58 and 58 extend rearward from this shaft oneach side of the block,

and these arms are pivotally connected by the links 59 to the sides ofthe yoke 60, which arches over the upper end of the plunger. An

adjustable contact between .the yokeand thev plunger is provided bythescrew 61 in the yoke, the lower end of which screw is adaptedv to enterthe cup-recess 62 in theupper end of the plunger.

The release-valve 63 is formedin-the upper end of the release-tube andthe valve proper.

preferably comprises a ball-valve resting in a cup and normally held upagainst itsseat in the end of the exit-port by a coil-spring, whichspring is sustained on the internal. annular. shoulder 64, formed in therelease-tube. limit and regulate the flow of oil through the axialexit-port 65 from the release valve, I

provide in this port the regulating-pinf66,v which pin abuts against theball-valve and .is-

constricted in diameter in the middle, to which part it is tapered fromeach end. The bell 6 7 rests on the upper end of the regulating-pin fromthe sleeve 71, which is journaled on the release-shaft 26,transverselymounted in the forward part of the block.. The release-arm 72 extends rearward from this sleeve along the side of the pump, and thisarm is piyotally connected by the link 7 3with the rear end of the idlelever 7 1, which is pivoted between the ears on the top of the pump. Theidle-lever and-its companion arm 74 are curved over the trunnions 76,which project from the sides of the release-valve bell, and bydepressing the releasing-lever, and thereby the idle lever, the bell iscarried downward, which pushes the regulating-pin and the ball-valvedown and opens the exit-port. This movement is limited by the adjustablestop-screw 77, which screw is located in the companion arm and strikesagainst the upper edge of the adjacent pump-ear.

depressed by means of the. lifting-lever 56, which extends, preferably,on

A- lower end of the regulating-pin.

The opening 'of the exit-port from the release-valveis increased as theregulating-pin is depressed, by reason of the reduced diameter of-thepin, so that the amount of flow of oil-from the release-valve can beregulated at will: by varying the depression ot :the releasing-lever,which is manipulated by the op erato'rs foot on the pedal 78. Thetransverse ports 79 are provided in the release-valveand lead: directly.from about the'middle of the exit-portadjacent to the reduced part ofthe regulating-pin to the sides of the valve, so as to afio'rda readyexit for the oil after it has entered the exit-port around the enlargedThe ends of the regulating-pin are made only slightly less in diameterthan the exit-port, and I preferto make one end of a little'lessdiameter than the other, so'that the initial amount of flow of oil fromthe release-valve can be varied by inverting .the'pin end for end. Itwill be understood that the regulatingpin can be made-single in'stead ofdouble, as illustrated and described, without affecting the nature ofthe inventionthat is, it can be tapered from the enlarged lower end to areduced upper end; but I prefer touse the doublepin because it gives agreater amount of variation by turning it end for end.

The piston-rod 80 operates in the piston- *cylinder and is providedwith'the usual head 81; The upper end of the piston-rod is attached tothebox-standard by means of the -bracke t'82, extending through andoperating in the slot,83, provided for it in the bodystandard. When thebox standard is ele-- vated, motion is conveyed to the body-standard. bymeans of the usual pulleys, as 84, pivoted on each inner side near thetop of the box-standard, and the chains 85, passing over the pulleys andattached to the base 5 and to the bodyastandard, as at 89.

The means for joining and manipulating the rotatable base on thefloor-plate and for entering and supporting the pump in the base, whichare illustrated and partly described, but not claimed, herein, are madethe subjectmatter of a divisional application filed March 28, 1904,Serial No. 200,247.

Whatl claim as my invention, and desire to secure by Letters Patent, is

1. In a chair-pump, a block having a reser-- voir therein and anaperturein the top, a cylinder in the reservoir, a spring-sustained plungeradapted to operate in the cylinder and hav- .-ing a bell-flange on itsupper end adapted to operate in the aperture and around the cylinder, ayoke having a bearing on the'plunger,

a rock-shaft mounted on the block and havingzlateral arms, andconnections between the yoke'and the arms.

2. 'ln achair-pump, ablock havingareleasetube therein, a spring-closedvalve in the tube,

anendwise-movable pin protruding from the tube and abutting on thevalve, a bell resting port; and means for actuating the pin.

4:. In a chair-pump, a release-tube having an exit-port therein, aspring-sustained valve adapted to close the inner end of the port, anendwise-movable tapered pin in the port having its enlarged end slightlysmaller than the port and abutting against the valve, with means forfree exit adjacent to the small end of the pin and means for actuatingthe pin.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

FRANK E. CASE. Witnesses:

HARRY FREASE, JOSEPH FREASE.

